Crystal Structures of Poly-Paraphenylene Oligomers Containing Pendant Phenyl Groups
DAYTON UNIV OH DEPT OF CHEMISTRY
Pagination or Media Count:
The room temperature crystal structure of 1.2.4.-triphenylbenzene TPB, C24H18, 2, 4-diphenyl-p-quinquephenyl DPQ, C42H30, and 2.6 -diphenyl-p- septiphenyl DPS, C54H38, have been investigated as part of a research programme in right-rod polymers, materials which are of great interest for aerospace and electro-optical applications. the molecules are non-planar, in contrast to the planar structures found at room temperature for the unsubstituted polyphenyls. The oligomer axis does not align with any of the crystallographic axes. The pendant-oligomer bond, however, does align with the longest crystallographic axis. The pendant torsion angle is greater than 45 and increases with increasing chain length. Knowledge of molecular structure and crystal packing of oligomeric model compounds will be useful in further calculations of mechanical, optical, and electro-optical properties for the corresponding rigid-rod polymer structures.
- Polymer Chemistry